• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3380-3389
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• 2022

We evaluated the performance of an improved hybrid median filter (IHMF) applied to X-ray computed tomography (CT) images obtained using a high-resolution photon-counting cadmium zinc telluride (CZT) detector. To study how the proposed approach improves the image quality, we measured the noise levels and the overall CT-image quality. We established a CZT imaging system with a detector length of 5.12 cm and thickness of 0.3 cm and acquired phantom images. To evaluate the efficacy of the proposed filter, we first modeled two conventional median filters. Subsequently, we were able to achieve a normalized noise power spectrum result of ~10^-8 mm², and furthermore, the proposed method improved the contrast-to-noise ratio by a factor of ~1.51 and the coefficient of variation by 1.55 relative to the counterpart values of the no-filter image. In addition, the IHMF exhibited the best performance among the three filters considered as regards the peak signal-to-noise ratio and no-reference-based image-quality evaluation parameters. Thus, our results demonstrate that the IHMF approach provides a superior image performance over conventional median filtering methods when applied to actual CZT X-ray CT images.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.196-202
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• 2021

This study sought to find importance factors for the quality of delivery food service, identify the mutual importance of delivery food service quality studied in the preceding study, and derive the order of importance of each factor. To compare the priorities of factors determining the choice of quality of delivery food service, this study used a decision model using the appropriate Analytic Hierarchy Process (AHP) and carried out the process of quantifying the mutual evaluation. This process allows us to view the relative importance and priority of the selection factors. Through a prior study, the main factors of quality of delivery food service were classified and the main people of high importance were selected. According to the results of AHP the quality of deliver service is the main factor for the quality of delivery food service, and the quality of order service and food service is the key factor of the quality of delivery food service, which should take the upper hand in importance. This study results in how important specific factors are by giving relative self-weights to the lower factors, showing that convenience and accuracy always have the first and second place weight priorities in the lower factors, despite differences such as gender age and frequency of making them more convenient and accurate.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.371-381
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• 2022

Since tributaries have greater water quality variability than main streams, a comprehensive evaluation method that considers the effects of various parameters rather than one water quality parameter has been introduced for effective water quality management of tributaries, but the characteristic of the watershed is not considered. In this study, the urbanization rate, livestock excreta generation, and industrial wastewater discharge in the Hantan River middle-watershed classify urban and non-urban watersheds, and evaluate the suitability of water quality indexes by watershed characteristics by analyzing water quality characteristics and calculating CCME WQI, RTWQI, and NSFWQI. Factor analysis was used to understand the effect of water quality parameters used to calculate the water quality index on the water quality index results. As a result of the factor analysis, the relationship between CCME WQI, TC, and FC was derived, and the relationship between RTWQI and DO, SS in urban watersheds and NSFWQI and FC in non-urban watersheds was revealed. As a result of evaluating suitability through comparison with BOD and T-P grades, it was interpreted that the suitability of the water quality index was low in urban watersheds and that comprehensive water quality evaluation using RTWQI was possible in non-urban watersheds.

• International Commerce and Information Review
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• v.12 no.2
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• pp.357-381
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• 2010

The purpose of this paper is to investigate the effects of consumer's preferences for foreign products and extrinsic cues such as brand, country of origin, and corporate reputation on the consumer's evaluation which includes the construct of perceived quality, and loyalty. In addition, this paper is aimed to provide Korean firms insights in strategic approaches about foreign consumers behavior. A conceptual model is developed and empirically tested against a sample of university students in Korea, who have buying experience of products from multinational firms. 290 samples were used for this analysis. Results of multiple regression analysis using SPSS 18.0 show that consumer's preferences for foreign products, brand awareness, and corporate reputation have a significant effect on the perceived quality of the product from multinational firms. The most important factor to influence the perceived quality was found to be a corporate reputation. But country of origin had not significant effect. Also it is found that both product and product related service quality are positive and statistically significant in explaining the customer's loyalty. Implications for increasing perceived quality and customer's loyalty for Korean products in the global market are discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1437-1442
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• 2006

The international competition in car markets has continuously required the research about the sound quality of a car. The domestic carmakers have also invested a lot of money for the research and development of interior sound quality of passenger cars. Therefore, the aim of this research is to predict the customer's evaluation of a new vehicle. There are two major research works to achieve this goal in this research. The first one is to search questionnaires about the sound quality, which customers prefer, to identify the relationship between these questionnaires and sound metrics that is a psychoacoustics parameters, and to development sound indexes for the questionnaires. All tests for this work is proceed on the road test during acceleration. The second one is to balance the sound component (engine noise, booming noise, road noise and wind noise) of a passenger. This wok will be tested on the constant speed. All of research results will be contributed to the development of brand sound quality of a new passenger car.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2328-2333
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• 2020

The filter technique was applied to noise images, as noise is the significant factor that cause poor image quality due to lower photon counting. The purpose of this study is to confirm that image quality can be improved using the median modified Wiener filter (MMWF) technique; this is achieved via a National Electrical Manufacturers Association International Electrotechnical Commission body phantom with four large spheres that are filled with the ^99mTc radioisotope when evaluating the image quality. Conventional filters such as Wiener, Gaussian, and median filters were designed, and signal to noise ratio, coefficient of variation, and contrast to noise ratio were used as the evaluation parameters. The improvement in the image quality was in the following order, from the least to the highest improvement, in all cases: Wiener filter, Gaussian filter, median filter, and the MMWF technique. The results show that the image quality was improved from 20.6 to 65.5%, 7.4-40.3%, and 12.7-44.7% for the SNR, COV, and CNR values, respectively, when using the MMWF technique, compared with the use of conventional filters. In conclusion, our results demonstrated that the MMWF technique is useful for reducing the noise distribution in gamma camera images.

• Journal of Information Technology Applications and Management
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• v.28 no.2
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• pp.35-41
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• 2021

This study sought to find importance factors for the quality of Mongolian consumers' evaluation for fresh food through online purchase. To compare the priorities of factors determining the choice of service quality of online purchase for fresh food, this study used a decision model using the appropriate Analytic Hierarchy Process (AHP). Through a prior study, the main factors of quality were classified as delivery quality, product quality, marketing, and system quality, respectively According to the results of AHP the quality of deliver information and deliver duration time under delivery quality are the main factor, followed by hygiene and freshness of product quality were the next highest. When consumers purchase fresh food through an online market. they considered deliver information, delivery duration time, hygiene, freshness, and deliver cost as important factors.

• Journal of Korean Society for Quality Management
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• v.31 no.4
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• pp.226-238
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• 2003

Recently, The problems with which our country's company is confronted for business of manufacturing goods. This study set the hypothesis to develop the method that was analysis and application of A reliability evaluation method of environmental material for circuit components in Computer, Color TV, Monitor, Microwave oven, Electric Refrigerator, Automobile parts, other goods. Especially, this study emphasis on regulate export of the EU and North America that it's a environmental material's hazards problem. In this process, this study set the pattern of practical application. Therefore, this study emphasis on the application of A reliability evaluation method of environmental material and the use of other parameters by environmental reliability test data. The result of this study is as follows. 1) There is relationship between regulate material and technical protecting system. 2) Characteristics of hazard materials is operating a healthcare damage factor as well as regulate environmental factors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.145-148
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• 2004

Until now, product mostly has revealed physical quantities created by the standpoint of engineers. Consumers, however, perceive and evaluate products on the non-physical characteristics, such as feelings, emotions, and experiences in different social and cultural situations. Especially, for the household appliances such as a refrigerator, the sound is heavily related to the satisfaction of a customer who is a real user of the product and is very important factor to decide purchasing as well as visual design. Therefore, in this research, not only the simple sound pressure level but also the consumer's sense of hearing evaluate the noise from the refrigerator. And also, in order to improve the quality of sound through the design change, the consumer's evaluation is analyzed and related to the engineering quantities.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.644-650
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• 2010

Among various elements to affect customer's evaluation of vehicle quality, BSR(Buzz, Squeak, Rattle) are considered to be a mostly contributing factor. In this paper, we provide the test method which can be used to reduce the BSR noise of instrument panel in a vehicle. First, potential source regions of the instrument panel for BSR are localized by using the vibration-excitor and near-acoustic field visualization system. Then, subjective evaluation of BSR noise from the detected potential noise source regions is made with the Zwicker's loudness and time-varying loudness methods. This illustrative analysis reveals that current experimental methods can be used as a test procedure to systematically tackle BSR issues in early stage of the vehicle development cycle, which can result in the reduction of the production cost.